Hardness
Very Hard
306 PPM · 17.9 GPG
Local water dashboard
Official source aggregationA source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Martin County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
306 PPM · 17.9 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0.001 mg/L
7% of action level
Utility match
1 system
Serves 10,328 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
306 PPM
Parts per million
306
mg/L as CaCO₃ equivalent
Grains per gallon
17.9
1 GPG ≈ 17.1 PPM
What this means at home
At 306 PPM, mineral scale can build up on fixtures and heating elements, reduce soap lather, and leave visible spotting. Hardness is primarily an aesthetic and appliance concern—not itself a tap-water safety rating.
USGS sites used
7
Nearest site
55.3 mi
Observation range
Jul 11, 2017–Aug 2, 2017
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 097N23W23ACC 1997NAWQA (Well).USGS source documentation ↗
Regional context
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Fairmont median
306 PPM
About the same1 indexed ZIP readings · Range 306–306 PPM
Minnesota median
318 PPM
12 PPM lower319 indexed ZIP readings · Range 46.1–716 PPM
EPA benchmark screen
Available numerical results from associated SDWIS community water systems, compared with the applicable action level or federal MCL. Federal measured-value coverage is incomplete.
Lead (PB90)
0.001 mg/L
Reported Dec 31, 2024
Copper (CU90)
Not available
No numerical 90th-percentile result
Numerical coverage
1 comparable result
Missing values remain blank; absence is not treated as a pass.
Measured in mg/L
Local 0.001
EPA limit 0.015
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Lead and Copper Rule | MN1460003 | Resolved | Jan 1, 2021through Apr 14, 2021 |
No reported violation does not prove that every contaminant was tested or absent; SDWIS measured values are incomplete and lag state records.
Solutions matcher
Matched to Fairmont ZIP 56031 using 306 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
306 PPM is 3× the high-hardness trigger used by this matcher.
Designed to reduce scale on fixtures, water heaters, glassware, and plumbing throughout the home.
Compare whole-house systemsAffiliate disclosure: we may earn a commission from qualifying purchases, at no added cost to you. Product matching is educational and does not replace certified water testing.
Frequently asked
EPA ECHO shows no active health-based violation for the associated systems in this reporting snapshot. This does not prove every contaminant is absent; federal records can lag and household plumbing can change tap conditions.
Nearby USGS observations produce an estimate of 306 PPM, or 17.9 grains per gallon, classified as very hard. This is not a household tap measurement.
At 306 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.